Hit a major plateau in my theory learning over the last 3 - or 4 months and i cant seem to find any information. Pretty much ive realised that il now how to pay for some brain food instead of getting my info from the web.

Anyway ill start but letting you know the things i do know so you can tell me where to go>

Major and Minor keys including commonly use chord substitutions (although i would like to learn more about this)
Chord construction + inversion - (limited when it come to sharpening on flattening certain degrees)
Basic cadences ( perfect , imperfect deceptive)
Very basic harmony principles

If anyone could advise me on a book to read to build of this knowledge it would be much appreciated

sorry should elaborated , i know how to flatten degrees , i know the fretboard in note and I play like , what I meant was is I don't really know to much about there harmonic function, i understand them as i use them for instance I get basically why a G#4 works well in B minor,, im really just looking for a book that will go into more detail then internet recources